sorry i was inclined to post something to try and help...i used to work on my RC's alot so im used to "fixing" things i dont prefer. it takes practice practice practice
Just kidding you...
Seriously, though, my efforts with hand tools don't always produce the best results. I'd be too nervous to try a frame modification unless I had a lot of trial runs first. I don't know how I'd do that with an M&P...so, if I do decide to try removing the rail, I'll have to send it off to a professional.